Typically the Supreme Court has defined these elements by identifying the circumstances in which qualified immunity would not be available. Referring both to the objective and subjective elements, it has held that qualified immunity would be defeated if an official "knew or reasonably should have known that the action he took within his sphere of official responsibility would violate the constitutional rights of the [plaintiff], or if he took the action with the malicious intention to cause a deprivation of constitutional rights or other injury ...." Id. (emphasis added).

Although it is true that we have observed that our determinations as to the scope of official immunity are made in the light of the "common-law tradition," 5 Malley, supra, at 342, we have never suggested that the precise contours of official immunity can and should be slavishly derived from the often arcane rules of the common law. That notion is plainly contradicted by Harlow, where the Court completely reformulated qualified immunity along principles not at all embodied in the common law, replacing the inquiry into subjective malice so frequently required at common law with an objective inquiry into the legal reasonableness of the official action. See Harlow, 457 U.S., at 815-820. As we noted before, Harlow clearly expressed the understanding that the general principle of qualified immunity it established would be applied "across the board."